Motion-picture projector



, May 3, 1949. L. H. MOOMAW 2,468,993

MOTION-PICTURE PROJECTOR Filed Oct. 17, 1946 5 Sheets-Sheet 2 fill/Illilllnla INVENTOR. LEW/s H. MOOMAW May 3,1949. L. H. MOOMAW 2,468,993

MOTION-PICTURE PROJECTOR 5 Sheets-Sheet 5 Filed Oct. 17, 1945 INVENTOR..LEW/S H. MOOMAW y 1949. L. H. MOOMAW 2,468,993

MOTION-PICTURE PROJECTOR Filed Oct. 17, 1946 5 Sheets-Sheet 4 -INVENTOR. 2/6 2/2 LE WIS H. MOO/HAW y 1949. 1.. H. MOOMAW 2,468,993

MOTION-PICTURE PROJECTOR Filed Oct. 17, 1946 5 Sheets-Sheet 5 INVENTOR.

LEW/S H. MOOMAW Patented May 3, 1949 UNITED t ll Fl lCE PRDJEIJTUR 17,1946, Serial No. 'lil fiilfi This invention relates to a motion pictureprojector, and more particularly to the projection machinery therefor.

In motion picture projectors, and particularly motion picture projectorsdesigned for home use, a single structure includes projection inachinery for moving film an illumination source for projection. purposes,a ventilating system for cooling the projector particularly to preventoverheating oi the film thereon, the film he ing at its point ofgreatest exposure to heat as it passes its projection position, and amotor for driving both the ventilating system and the nrojectionniacl'iinery. It is necessary that means he provided to so adjust theprojection machinery that during those instants the film is exposed forprojection. the frames thereof correspond to the light passingtherethrough so that only a single picture, and not portions or a pairof pictures, is pro ectecl at time. Since it may be desired to stop thmotion picture projection in order to exhibit single frame of the filmin still projection, means must also he provided for connecting toprojection machinery from its driven relations o with the motor. Duringsuch time as the film remains stationary and exposed to the full forceof the Q1 lated by the light source, the projector must provideadditional protection from heat therefor lest it he scorched ordestroyed.

t is a prime object or the present invention to provide an assembly ofprojection machinery such that a cove fcatr are obtainable in a simplemanner.

It is another object of the present invention to provide novel 11 ns fordisconnecting the projec tion machinery rrcro. the motor so as to permitstill rather than moving exhioition of any desired frame.

It is a further object oi the present invention to achieve the above insuch a manner as to simultaneously obtain creased ventilating action theprojector as to prevent scorching film.

It is still another object of the inven tion to provide adjustable meanscontrolling the projection machinery so that the whole of si gle frameof film may be pro" nually associated therewith of such a nature thatthe fire shutter will interpose itself between the light source and thefilm when the speed of projection is so slow as to jeopardize the safetyof the film if exposed to the full force of the illuminating source, thefire shutter thus acting to aid the increased cooling effect of theventilating system when the motor has been declutched from theprojection machinery.

To the accomplishment of the foregoing objects and such other objects asmay hereinafter the present invention relates to the arraneement or" theprojection machinery as sought to be defined in the appended claims andas descrihed in detail n the accompanying specification taken togetherwith the appended drawings, in which:

1 is a three-quarter rear perspective View of a projector embodying thefeatures of my invention;

Fig. 2 is a View of the projection machinery taken along the line 2-2 ofFig. 1;

Fig. 3 is a schematic View of the transmission system;

Fg. l is a view along the line 6- of Fig. 5;

5 is a view taken along the line 22 of 1, but showing only the clutchmeans as herein embodied;

Fig. 6 is a side View, partially cross-sectioned, of the driven pulley;

'7 is a view taken along the line 'l'! of g. s is a View taken along theline 22 of Fig. i, but showing only the framing mechanism, the shutterand associated control apparatus;

9 is a view taken along the line 9-9 of Fig. 10;

Fig. 19 is a rear view of the claw arm oscillating means;

Fig. 11 is a side view of the claw arm oscillating means as mounted inthe projector housing;

Fig. i2 is an exploded view of the fire shutter associated controlapparatus;

3 is a front view of the rotating element cts as the shutter; and

- i4- is a side View thereof, taken along the line l t-i i of 13 showingit mounted in the c-rojector hon This application describes my inventionas em- :odied an a millimeter home projector, other ieatu c. of whichare described with more particularity in my co-pencling applications,Ser1al No. 798,805 Gctcher i7, 19%, now Patent Numb-er 2,440,966, issuedMay l, 19%, Serial No.

703,806 filed October 17, 1946, and Serial No. 703,807 filed October 17,1946.

It is to be understood, however, that my invention is not confinedspecifically to such a pro- J'ector.

My projector generically comprises a ventilating means A and projectionmachinery B, both adapted to be driven by the same motor C. A manuallyoperable clutch means D is interposed between the motor C and theprojection machinery B so that the projection machinery may be pped topermit still projection while the motor C continues to rotate. Theclutch means D is so constructed that when the projection machinery B isdisconnected or declutched from the motor C, the reduction of load onthe motor C causes it to rotate more rapidly, whereby the ventilatingmeans A is driven more rapidly, an increased ventilating effect isobtained, and consequently the film is subj eoted to an increasedcooling effect at the very time that that cooling effect is most needed,to wit, when the film is stationary.

As is well-known in the art, it is essential that the film move past thelight source in intermittent steps. A film moving element E, here shownas a resilient claw arm, accomplishes this function.

The film moving element E is oscillatable about a pivot F which in turnis mounted on a movable member G so as to be movable within limitsinside the projector. By adjustment of the position of the pivot F, thefilm moving element E can be so coordinated with the remainder of theprojection machinery B that the projected images will be framed, that isto say, projection will take place with respect to but a single frame ofthe motion picture film at a time, and not with respect to portions of apair of adjacent frames. The position of the pivot F can, in myprojector, be manually adjusted by suitable actuation in eitherdirection of a continuously rotatable member H, so that proper framingmay be attained by rotation of the member H in either direction anydesired amount, thus eliminating the inconvenience attendant uponconventional framing means which generally employ a screw the rotationalfreedom of which is limited. With the conventional type of framingmechanism, the operator, if he is uncertain in which direction to rotatethe screw in order to frame the projection, will try one direction toits limit and, if efiective adjustment is not achieved thereby, mustretrace his steps by rotating in the opposite direction. However, withmy framing mechanism, rotation in either direction will reciprocate thepivot F in the projector housing and thus will permit accurate framingwithout any lost motion or retracing of steps.

A rotating means J is provided to cause the film moving element E tooscillate about its pivot F. A speed-sensitive centrifugal means K isconnected in driven relation with the rotating means J, and is hereshown as carried by the rotating means J itself, the means K beingactive upon positioning means L so as to determine the position whichthe fire shutter M takes with respect to the film and the illuminationlamp (not shown). When the film is projected while moving, a givenportion of the film is exposed to the full force of the illumination,and consequently is subjected to its greatest exposure to heat, for onlya short period of time. It is therefore not necessary that the fireshutter M be interposed between the film and the light source duringsuch moving projection. To this end the centrifugal means K is soconstructed that when the rotating means J is moving at suflicientspeed, the centrifugal means K so actuates the positioning means L as toensure that the fire shutter M is in its raised position, as shown inFig. 2.

When the motion of the film is stopped for projection of single framethereof in still projection, a small portion of the film is exposed tothe full force of the illumination for an extended period of time andconsequently critical danger or" scorching or other damage due to heatexists. During still projection, the rotating means J is stationary andthe centrifugal means K, positioning means L and the fire shutter M soco-act that under these conditions the fire shutter M is interposedbetween the film and the illumination source so as to shield the filmfrom the full force of the illumination and consequently to insulate thefilm to some degree from the heat emanated from the illumination source.Such a position of the fire shutter M is shown in Fig. 8.

It is to be noted that this action of the fire shutter M acts in aidingconjunction with the ventilating means A, motor C and clutch means D. Tooperate the projector in still projection, the clutch means D must be soactuated as to disconnect the projection machinery B from the motor 0.When this has been done, not only will the rotating means J stop, thusensuring that the fire shutter M is in its interposed position, but, hasalready been described, the reduction of load on the motor C, whichremains connected to the ventilating means A, results in an increasedventilating action, and thus in an increased cooling effect.

Having thus described the generic principles involved in my novelventilation system, I shall now describe a portable home motion pictureprojector embodying these principles in a very compact and efiicientstructure. The drawings and the description relate specifically to aprojector of my invention adapted to receive 8 millimeter film and henceof comparatively small size, but the principles above set forth may, ofcourse, be employed in movie projectors of other sizes, both portableand non-portable, without departing from the spirit of my invention.

My projector comprises a base 2 in which is housed the variouselectrical control circuits for the projector, those circuits comprisingan illumination circuit for the lamp (not shown) controlled by switch 4,a start and stop circuit for the motor C, controlled by switch 6, and areversing switch for the motor C, controlled by switch 8. Knob I0 maycontrol a rheostat in the motor circuit so as to control within limitsthe speed of rotation thereof and consequentl; the speed of projection.Electrical connection is made to these circuits by means of the contactpins l2. The projector housing proper, generally designated M, ismounted in the base 2 in such a manner as to be tiltable with respectthereto so as to control the position of the projected image, the knobIE on the base 2 controlling the tilt.

The housing l4 comprises a fan housing [8 provided with air inletorifices 20 in which is disposed a ventilating fan 54 (shown in phantomin Fig. 1), a lamp hOllSlIlg 22 in which is disposed an illuminationlamp (not shown), a motor housing in line with the fan housing IS inwhich is disposed a motor 0, shown in phantom in Fig. 3, a projectionmachinery housing 24, a gear box housing 25, a pair of reel supports 28and 30 rotatably mounted at the extremities of reel arms 32 and 34,conventional sprocket assemblies 36 and 38 for guidin the film, anaperture plate 40 sigma-993 light from the illumination lamp to an areaequivalent to one frame of the motion picture film and a gate Mlhingedly attached thereto by piano hinge 6 for maintaining the film incontact with the aperture plate Ail and carrying lens assembly 4'8 forproperly directing and focus-- ing the projected image. All of the aboveelements may be, except as hereinafter specifically described, ofconventional construction insofar this invention is concerned. Detailsof various features thereof not more specifically described herein maybe found in my co-pending applications for Letters Patent enumeratedabove.

Rotation transmitting system and clutch means The source of motion forall of the moving parts of my projector is a single motor C, to thedrive shaft Ell of which is connected a driving pulley 52 and the fan 54which comprises part of the ventilating means A. The drivin pulley 52 ishere shown as provided with a pair of tapered circumferential grooves %6(see Fig. 4), into which the mating circumferential projections 58 ofeach of the two friction pulleys BS and t8 adapted to project;

Each of the friction pulleys 59, 69 comprise a hub 62 press-fitted overbushing 63, which is freely rotatable on shaft cc itself in turn carriedby arm 56 which is pivotable about screw 68 suitably attached to theprojection machinery hous-- ing 24. The body of helical spring iii iswrapped around the screw 68, one end 12 thereof being suitably securedto the frame Z l as by screw it and the other end l6 thereof exertingpressure upon the arm 65 in such a direction as to force the frictionpulley ill into contact with the driving pulley 52.

Secured to the hub 62 by means of screw H3 is a body of frictionalmaterial such as cork or rubher, the peripheral edges of which areprovided with the circumferential projections 58. The force exerted bythe spring in is sufficient toen sure that the friction between thedriving pulley 52 and the friction pulleys to and 60 will be ofsufficient magnitude so that the former will drive the latter.

The extremities of the arms 66 and 85 terminate in ledges 8i} and 80'.Rotatably mounted in the housing 2d so that its projecting extremity isinterposed between the ledges 88 and 8t of the arms 65 and 66 is shaft82, the other end of which projects out through the wall of the hous ing24 and has attached thereto an actuating knob 65. The end of the shaft82 which is interposed between ledges 8d and 89 has disposed thereon apair of radially projecting pins St, the projecting lengths of which aresufficient so that when they are disposed perpendicular to the ledges88, til they will spread the arms (it, til against the action of thespring it, it and thus move the friction pulleys ti) and 6% out ofcontact with the driving pulley 52. This position is illustrated in Fig.3.

The shaft 82- may also carry a shell iii! provided with a pair ofnotches til, 9!! which cooperate with a spring-loaded detent mounted inthe housing 24 in order to ensure positive position ing of the shaft 82and the pins [it between a sition in which the pins 88, 85 do not makecontact with the ledges til, at and a position in which such contact ismade and the are thereby spread apart.

A driven pulley 94, similar in construction to the driving pulley 52 butoptionally differing therefrom in size, is mounted in the housing 24 soas to'bc rotatable about a shaft 96. The tapered' circumferential rooves5b of the driven pulley 54 are located in line with the similar grooves56 of the driving pulley 52 and with the frictional circumferentialprojections 63 of the friction pulleys E38 and 60 so that when thesprings 'l'll'and ill urged the friction pulleys t9 and 6d intofrictional contact with the driving pulley 5'2, similar contact issimultaneously ensured between the friction pulleys 68 and 60' and thedriven pulley M by which means rotation of the driving pulley 52 istransmitted thereto.

Gear 8 carried by the driven pulley 94 meshes with'anddrives gear lllilwhich is in turn rigidly attached to shaft gear Hi l and cam Hit. Theshaft I82 is rotatably supported in the rear wall 243 of the projectionmachinery housin 2d and projects through the gear box housing 25 toterminate in externally attached knob led. To that portion of the shaftHi2 within the gear box housing 25 is secured, by means of set screw H8in conjunction with shaft notch H2, a worm gear lid, rotation of whichdrives gear Ht, sprocket wheel H8, gear 23 and shaft H22. To sprocketwheel M8 is attached sprocket chain ltd which drives, through suitablemechanism, the reel support 23. To shaft is attached the sprocketassembly Gear its meshes with and drives idler gear and large idler gearI30. The

' gears iii-i lSd rotate gears I32 and [34,

respectively, each at a difierent speed because of parts control therotation of the reel supports 28 and 3t and the sprocket assemblies 36and 38, it will be apparent that when the friction pulleys ti and Gilmake contact between the driving pulley and the driven pulley 94, thefilm in the projector will be caused to move until, by rotation of theknob t l, the pins 86 in conjunction with the ledges til and till movethe friction pulleys iii and away from frictional connection with thedriving pulley 52 and the driven pulley 9d, at which time motion of thefilm through the projector will cease. Selection of the desired framefor still projection can be effected by rotation of the lrnob its andwill have the elfect of manually moving the projection machinery withoutthe aid of the motor. It is therefore apparent that the friction pulleys$8 and and the means by which they are mounted in the projector comprisethe clutch D which may be positively actuated by the rotation of theknob 84 through but small angle and which, when actuated so to declutchthe projection machinery from the driving pulley thus remove the load ofthe projection machinery from the motor C, enabling the motor to rotatemore rapidly and thus to drive the fan 54 at increased speed, achievingan increased cooling efiect within the projector.

Framing mechanism As is well-known, projection of motion pictures isaccomplished by the successive projection of a large number of separatepictures, each for a small period of time. It is, therefore, necessarythat the film be moved past the light aperture 42, through which passeslight from the illumination source, not at a continuous speed but in aseries of discrete steps or jerks. It is further necessary that light bepermitted to pass through the film to the projection screen only duringsuch instants as the film is stationary, and it has been found thatsmoothness of projection is enhanced if, during the period that the filmis stationary, a series of short light pulses be permitted to passthrough it.

To this end, my projector includes a rotating element I42 (see Figs. 2,13 and 14) attached to hub I44 and gear I45 by means of screw I48 andlock nut I50, the entire assembly being freely rotatable upon shaft I52mounted in the rear of the projection machinery housing 24. The gear I45engages with and is driven by the gear I04. The rotating element I42 isprovided with a plurality of blades I54 of size sufiicient to interposethemselves, as the element I42 rotates, between the illumination sourceand the light aperture 42 (see Fig. 2) thereby alternately interruptingand permitting the passage of light through the aperture 42. The bladesI54 consequently act as the shutter for the projector.

In order to control the movement of the film past the light aperture 42,a film moving element E is provided, here shown in the form of a clawarm formed of a resilient material such as spring steel. One end I55 ofthe film moving element E is so connected to bar I58 mounted within theprojection machinery housing 24 as to be pivotable with respect theretoabout a pin F which defines the pivot therefor. The other end I60 of thefilm moving element E projects out through an aperture 62 in a wall ofthe housing 24 and has a pair of claws (not shown) thereon to engagewith the sprocket holes of the film and thus positively control themotion of the film past the light aperture 42.

The central portion of the film moving element E is cut out as at I64and is provided with a pair of bearing surfaces I60, I66 which receiveand fit snugly against the periphery of the cam I06. The cam I06 iseccentrically mounted upon the shaft I02 and is so shaped that rotationof the cam I will cause the film moving element E to oscillate about itspivot F and thus cause the claws on the end I00 thereof to move up anddown, two complete oscillations of the film moving element E beingproduced for every complete rotation of the cam I06.

In order to permit the claws on the end of the film moving element E todisengage themselves from the sprocket holes in the film at suitableintervals and also in order to permit the passage of a plurality ofpulses of light to pass through the film during each of its stationarypositions, the film moving element E is so positioned and constructed asto have its end I60 resiliently urged away from the film in theprojector and into contact with the underside I68 of the rotatingelement I 42. As will be apparent from an inspection of Figs. 13 and 14,one segment of the outer portion of the underside I38 of the rotatingelement I42 is provided with a raised cam surface I10. When the camsurface I comes into contact with the film moving element E, the elementE will be bent toward the film an amount sufflcient for the claws on theend I60 thereof to engage with the sprocket holes and move the film anamount sufficient to bring the next succeeding frame of the film intocorrespondence with the light aperture 42.

It will therefore be apparent that the precise position that the filmtakes up during any movement of the projector with respect to the lightaperture 42 is controlled by the precise position of the film movingelement E with respect to the other projection machinery. It oftenoccurs that the film is positioned so that the light aperture 42 doesnot coincide with a complete frame or single picture on the film butrather coincides with parts of a pair of adjacent frames. It isconsequently necessary to provide means for framing the film in orderthat the whole of a single picture and not parts of a pair of adjacentpictures be projected at any one time. The framing means here employedachieves adjustability by altering the position within the projectorhousing of the pivot F of the film moving element E. All prior framingmechanisms of this nature have the drawback that actuation of the manualcontrol means therefor in a given direction will achieve only a limitedchange in the position of the pivot F and should such change, whencarried to its limit, prove insufficient properly to frame the film, thecontrol means must thereupon be moved in its opposite direction in orderthat framing might be effectuated.

I eliminate the necessity for such false starts and lost time and energyby providing a framing mechanism manually actuatable by means of knobI12, which knob may be turned in either direction an unlimited amount inorder to achieve full framing action in both directions.

To that end the shaft I14, to which the knob I12 is attached, hasprojecting from its extremity a pin I16 eccentrically mounted thereon(see Figs. 2 and 8) which constitutes the continuously rotatable memberH.

The bar I58 to which the film moving element E is attached by means ofpivot F is itself secured to the projection machinerv housing 24 bymeans of screws I 8 and I which pass through elongated slots I 02 andI84 in its body, the bar I58 thus constituting the movable member G prevously referred to. The upper end of the bar I58 is p ovided with aninwardly bent forked pro ection I86 between the tines of w ch ro- .iectsthe pin I16. Therefore, rotation of t e. knob I12 and consecment ro aton of the pin I16 will cause the bar I58 to reciprocate wi hin t e hosing 24 and thus the pos tion of the pivot F of the film movin element Ewill be varied between its extreme positions.

Fire shutter and positioning means therefor The fire shutter M isadapted to cover the light aperture 42 by interposing itself between theaperture 42 and the illumination source when the motion of the film pastthe aperture 42 has either stopped or is of such a low velocity as toexpose the film to extreme danger of damage from heat. The shutter M isa perforated metal plate, through the perforations of which a restrictedamount of light may pass, thus permitting still projection butrestricting the amount of heat to which the film is subjected, and ismovable over its supporting plate I90 between its position shown in Fig.2, where it does not obstruct the light aperture 42, and its positionshown in Fig. 8 where it does. It is provided with 9 a projecting lugwhich extends through a slot let in an upturned on the plate I90 andpositively limits the ir eoorn of motion of the shutter M.

The gear attache to shaft W2, is countersunk as at see 9, l and i2) anda pair of arms and mounted in said coun i otable about pins its The armsand are each mounted on pins and in an inn balanced condition so thatwhen the gear rotates, h ler ends of 266i and will be it fugally forcedoutward causing the arms and to pivot about the pins and Jr of each ofthe arms are l e shown provided with upstanding fingers and HE.

A disc Eli? (see 3 l2) provided h pin El i is loosely mounted or so tobe independently r tatable respect thereto and is of such a as to beloosely receivable between the i an Elli oi the ls and its If the gearat an eaceedingy file will have effect of any consequence on the discHowever, as soon as the speed of rotation of the gear its becomessufficient to cause the arms and to pivot about the pins and the fingersits will come in contact w h and grasp the periphery of the disc 252 andwill to rotate the disc 7;!2 along with themselves.

As the disc 252 is thus rotated th pin its, carried thereby, will comeinto contact with one or the other of the shoulders 22G ills of the armare which is mounted on the housing it so as to be rotatable about pinThe arm is provided with an upwardly projecting portion 226 which, whenraised by the action of the pin 2M on shoulder 2 i 3 or iii-l, cot-.nescontact with and raises pin E26 attached to am are which is pivotable atone extremity about pin and which carried at its other extremity thefire shutter M.

The upward motion of the fire shutter M is limited by contact of the luglull attached thereto with the upper end of the slot its in which itrides. Consequently, the upward motion of the pin 22% and the arm isimilarly limited and therefore rotation of the disc 2E2 beyond thatsufficient to lift the fire shutter M to its position shown in Fig. 2 ispositively prevented. The gear Hill continues to rotate, the fingers(stow and 2H] continuing to grasp and slide over the peri hery of thedisc 262 and continually exert frictional force tl' ereupon to maintainthe fire shutter M in its raised position.

Should the gear sec cease turning, as for example if the clutch means Dwere actuated to do clutch the proiection machinery from the drivingpulley 52, or if for any reason the speed of rotation of the gear assshould fall below that which ensures safety of the film from adverseheat effects, the frictional force exerted by the fingers 208 and 25s onthe disc 252 would no longer be sufficient to overcome the combinedweights of the pin 2 Hi, the arm 225i, the pin 22.1%, the arm and thefire shutter M, and consequently all of those elements would fall totheir lower position as shown in Fig. 8, the downward motion of the arm220 being limited by the shaft iii-2 and the downward motion of the fireshutter li/i being limited by the engagement of the lug ass with thebottom of the slot its in which it rides.

The operation and interaction of the various elements of the projectionmachinery which I have described will in the main be fully apparent fromthe above recital. It will be apparent that many changes in detail maybe made therein wl hcut departing from my invention as set forth withmore particularity in the appended claims:

claim:

A mot on picture projector comprising a ve means therein, a claw arm atbly mounted therein for moving the film, a rot ng active upon said clawarm to oscillate the same, a motor connected to drive both the imeansand a driving pulley,

position inov' picture projection in which it makes contact with andconnects the driving pulley and the driven pulley and a second positionfor still picture projection in which it does not rnalze contact withboth the driving and driven pulleys, a fire shutter movable within saidframe between a first posi ion for moving projection and a second pos onfor still projection, centrifugal means in driven connection with saidrotating means, and positioning means normally plac ng shutter in itssecond position and actuatable by said centrifugal means when therotating means exceeds a critical rotational speed to place fire shutterin its first position, whereby when said friction pulley is in its firstpositiorfor moving picture projection the motor drives the ventilatingmeans, oscillates the claw arm to move the film, and causes the fireshutter to be placed in its position, and when said friction pulley isin second position for still picture projection the motor drives theventilating means at increased speed so as to increase the coolingeffect thereof and increase the safe duration of still pictureprojection, the claw arm is not oscillated so that the film is still,and the fire shutter is caused by its positioning means to assume itssecond position.

2. A motion picture projector comprising a frame, ventilating meanstherein, a claw arm mounted therein so as to be oscillatable about apivot 15 or moving the film, a rotating means active upon said claw armto oscillate the same, means for varying the position of said claw arinpivot comprising a movable member which carries said claw arm pivot anda continuously rotatable member active upon said movable member toposition same, a motor connected to drive both the ventilating means anda driving pulley, a driven pulley connected to drive said rotatingmeans, a friction pulley movable between a first position for movingpicture projection in which it roalzes contact with and connects thedriving pulley and the driven pulley a second position for still pictureprojection in which it does not make contact with both the driving anddriven pulleys, a the shutter movable within said fr me between a firstposition for moving projection and a second position for stillprojection, centrifugal means in driven connection with said rotatingmeans, positioning r ally placing said fire shutter seco and actuatahlesaid centrifugal. means when the rotating means exceeds a criticalrotational speed to place said shutter its first position, whereby whosaid friction pulley is in its first position for moving pictureprojection the motor drives the ve llating means, oscillates the clawarm to move the iilni, and causes the shutter to be placed in its firstposition, the posi" tion of the claw arm pivot being at the same timeadjustable to frame the film being projected, and when said frictionpulley is in its second position for still picture projection the motordrives the ventilating means at increased speed so as to increase thecooling effect thereof and hence increase the safe duration of stillpicture projection, the claw arm is not oscillated so that the film isstill, and the fire shutter is caused by its positioning means to assumeits second position.

3. An adjustable framing mechanism for a motion picture projectorincluding a housing, a film moving element and an actuating means forsaid element oscillatable about a pivot; said mechanism comprising amovable member which carries said pivot and a member manually rotatablein a given direction an unlimited number of revolutions and active uponsaid movable member to reciprocate the same between its limits of motionupon rotation of said manually rotatable member in a single directionand thus adjust the framing of the film in said projector.

4. An adjustable framing mechanism for a motion picture projectorincluding a housing, a film moving element and an actuating means forsaid element oscillatable about a pivot; said mechanism comprising amember movable within limits within said housing which carries saidpivot and a member manually rotatable in a given direction, and aneccentric connection between said rotatable member and said movablemember to reciprocate the latter between its limits of motion uponrotation of said rotatable member in a single direction, therebyadjusting the framing of the film in said projector.

5. An adjustable framing mechanism for a motion picture projectorincluding a housing, a film moving element and an actuating means forsaid element oscillatable about a pivot; said mechanism comprising amovable member which carries said pivot, a member manually rotatable ineither direction an unlimited number of revolutions and active upon saidmovable member to reciprocate the same between its limits of motion uponrotation of said manually rotatable member in a single direction andthus adjust the framing of the film in said projector.

6. An adjustable framing mechanism for a motion picture projectorincluding a housing, a film moving element and an actuating means forsaid element oscillatable about a pivot; said mechanism comprising a,member movable within limits within said housing which carries saidpivot, a member manually rotatable in either direction, and an eccentricconnection between said rotatable member and said movable member toreciprocate the latter between its limits of motion upon rotation ofsaid rotatable member in a single direction, thereby adjusting theframing of the film in said projector.

7. An adjustable framing mechanism for a motion picture projectorincluding a housing, a film moving element and an actuating means forsaid element oscillatable about a pivot; said mechanism comprising a,movable member which carries said pivot and a member accessible from theoutside of said housing and manually rotatable in a given direction anunlimited number of revolutions and active upon said movable member toreciprocate the same between its limits of motion upon rotation of saidmanually rotatable member in a single direction and thus adjust theframing of the film in said projector.

8. An adjustable framing mechanism for a motion picture projectorincluding a housing, a

film moving element and an actuating means for said element oscillatableabout a, pivot; said mechanism comprising a member movable within limitswithin said housing which carries said pivot, a member accessible fromthe outside of said housing and manually rotatable in a given direction,and an eccentric connection between said rotatable member and saidmovable member to reciprocate the latter between its limits of motionupon rotation of said rotatable member in a single direction, therebyadjusting the framing of the film in said projector.

9. An adjustable framing mechanism for a motion picture projectorincluding a housing, a film moving element and an actuating means forsaid element oscillatable about a pivot; said mechanism comprising amovable member which carries said pivot, a member accessible from theoutside or" said housing and manually rotatable in either direction anunlimited number of revolutions and active upon said movable member toreciprocate the same between its limits of motion upon rotation of saidmanually rotatable member in a single direction and thus adjust theframing of the film in said projector.

10. An adjustable framing mechanism for a motion picture projectorincluding a housing, a film moving element and an actuating means forsaid element oscillatable about apivot; said mechanism comprising amember movable within limits within said housing which carries saidpivot, a member accessible from the outside of said housing and manuallyrotatable in either direction, and an eccentric connection between saidrotatable member and said movable member to reciprocate the latterbetween its limits of motion upon rotation of said rotatable member in asingle direction, thereby adjusting the framing of the film in saidprojector.

11. A motion picture projector comprising a housing a claw arm forcontrolling the motion of the film. actuating mechanism for said clawarm, a pivot to which said actuating mechanism is oscillatablyconnected, and adjustable framing mechanism comprising a member mountedin said housing so as to be slidable within limits and carrying saidpivot and a cam continuously manually rotatable in a given directon andactive upon said member to slidably position the same in said housingand thus position said pivot, thereby adjusting the framing of the filmin said projector.

12. A motion picture projector comprising a housing, a claw arm forcontrolling the motion of the film, actuating mechanism for said clawarm, a pivot to which said actuating mechanism is oscillatablyconnected, and adjustable framing mechanism comprising a member mountedin said housing so as to be slidable within limits and carrying saidpivot and a cam continuously manually rotatable in a given direction andactive upon said member to reciprocate it between its limits of motionand hence position said pivot, thereby adjusting the framing of the filmin said projector.

13. A motion picture projector comprising a housing, a claw arm forcontrolling the motion of the film, actuating mechanism for said clawarm, a pivot to which said actuating mechanism is oscillatablyconnected, and adjustable framing mechanism comprising a member mountedin said housing so as to be slidable within limits and carrying saidpivot and a cam operable from the exterior of said housing, continuouslymanually rotatable in a given direction, and active upon said member toreciprocate it between its limits 13 of motion and hence position saidpivot, thereby adjusting the framing of the film in said projector.

14. A motion picture projector comprising a housing, a claw arm forcontrolling the motion of the lm, actuating mechanism for said claw apivot to which said actuating mechanism is osciilatably connected, andadjustable framing mechanism comprising a member mounted in said housingso as to be slidable within limits and carrying said pivot and a camoperable from the exterior of said housing, continuously manuallyrotatable in either direction, and active upon said member toreciprocate it between its limits of motion and hence position saidpivot, thereby adjusting the framing of he film in said projester.

15. A motion picture projector comprising a housing, a claw arm forcontrolling the motion of the film, a, pivot to which said claw arm isoscillataoly connected, and adjustable framing mechanism comprising abar slidably mounted in said housing and carrying said pivot, arotatable knob mounted on the outside of said housing and continuouslymanually rotatable in either direction, and an eccentric in said housingrotatable by said knob and engageable with said bar, rotation of saidknob rotating said eccentric and reciprocat- 14 ing said bar within saidhousing, thus varying the position of said pivot, whereby framingadjustment of said ciaw arm from one extreme to the other and back againis accomplished through continued rotation of said knob in eitherdirection.

LEWIS H. MOOMAW.

CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 940,275 Pink et a1 Nov. 16, 19091,227,282 Connor et a1. May 29, 1917 1,8 6,994 Green Feb. 16, 19321,899,149 Marks Nov. 29, 1932 1,926,862 Wellman Sept. 12, 1933 1,982,739Kaden et al. Dec. 4, 1934 2,199,653 Githens et a1 Feb. 20, 19402,259,591. Sperry Oct. 21, 1941 2,281,725 Stechbart May 5, 19422,282,863 Githens et a1. May 12, 1942 2,392,311 Stechbart Nov. 24, 19422,335,435 Morgan et a1. Nov. 30, 1943 2,335,436 Morgan et al Nov. 30,1943

